2008 Volume 49 Issue 3 Pages 527-531
Copper and iron are immiscible elements according to the equilibrium phase diagram, but they can form metastable phases by mechanical alloying process.
In this present work, mixtures of Cu-Fe powders in the range 0, 12, 25 and 40 atomic% of Fe have been prepared by ball milling. The analysis of alloyed samples shows a single phase described in the fcc-Cu structure, except for the 40%-Fe compound, which presents the additional bcc-Fe phase. The study of microstructure and magnetic properties under thermal treatments suggests a decomposition of the metastable phase with increasing temperature.
In the Cu-richer domain, the fcc cell parameter increases with increasing Fe content. This effect is explained from the fact that the ferromagnetic Fe phase is dispersed in the form of nanosized particles in the paramagnetic Cu matrix, in agreement with previous reports.